载体助剂对环氧乙烷银催化剂性能的影响

Effect of carrier additives on the performance of ethylene oxide silver catalyst

采用Zr和Cr助剂改性银催化剂载体氧化铝,探索影响环氧乙烷合成银催化剂初期选择性的关键因素。结果表明,载体中添加的Zr和Cr助剂,负载的银粒子及协同助剂均未在氧化铝表面形成较强的酸性中心,Zr和Cr组分间存在协同效应,促进高价态的Re元素的形成,Zr组分能激发出特征峰信号更强的Cr2p峰。添加Zr助剂的载体与不加Zr的载体相比,在强化负荷条件下,制成的银催化剂初期选择性高出约2%,初期反应温度高出约6℃。

The silver catalyst support Al 2O 3 was modified by Zr and Cr promoters to explore the key factors affecting the initial selectivity of the ethylene oxide synthesis catalyst.The results showed that Zr and Cr promoters added in the carrier,as well as the subsequent loading of silver particles and their synergistic additives,did not form strong acid centers on the alumina surface.There was a synergistic effect between the Zr component and the Cr component,which promoted the formation of Re element in the high valence state.The Zr component could excite the Cr 2p peak with stronger characteristic peak signal.Compared with the carrier without Zr,silver catalyst with Zr promoter added in the carrier had an initial selectivity of about 2% higher under enhanced load conditions,and the initial reaction temperature was about 6 ℃ higher.